Operating in the dark would be challenging for most surgeons. But for Indiana University Health's Dr. Emma Rossi, a dimly lit room can be as critical as a scalpel.

Rossi has been testing a new procedure to track the spread of gynecological cancers. She injects a fluorescent dye that glows in the dark into a patient and dims the lights in the operating room. Then she uses infrared imaging to track the path the cancer might have taken.

"We're trying to find the road that the cancer traveled on, because otherwise the road is invisible," said Rossi, an assistant professor of obstetrics and gynecology at the Indiana University School of Medicine.

Other doctors do this procedure, but it lacks government approval. Nor is there any evidence that it results in better outcomes than traditional surgeries.

So Rossi is leading a multicenter trial to compare old and new methods for treating gynecological diseases such as cervical and uterine cancer.

First, Rossi injects the dye that will light up the lymph nodes. She removes the ones that the dye pinpoints. Then she proceeds as usual, taking out the patient's uterus and other lymphatic tissue. A robot assists her, and the operation is minimally invasive, entailing only a few narrow incisions.

After the surgery, pathologists check lymph nodes for cancer. Often uterine cancer grows slowly and will not have spread. But when it has, Rossi hopes the dye will have located any cancerous nodes, indicating the patient should undergo chemotherapy.

Fewer side effects?

"It works; you can find lymph nodes with it," Rossi said. "But are these the lymph nodes that the cancer is in? We want to see that wherever there's cancer in the lymph nodes, that it's always in the lymph nodes that had dye."

Current treatment of gynecological cancers involves removing all tissue that could contain affected lymph nodes. That comes with the risk of side effects and complications, including swollen legs and nerve injuries.

The new procedure, called sentinel node mapping, could greatly reduce the number of lymph nodes that need to be removed.

A definitive answer could arrive too late to help Pamela Flannagan, a 68-year-old Avon, Ind., resident, but that didn't stop her from agreeing to participate in the trial.

A few years out from a leukemia diagnosis, Flannagan recently learned she had uterine cancer. She went to Rossi for a pre-surgical consultation and heard about the trial.

"I said, if it would help someone else, I would be glad to do it," she said. "I hope it helps someone down the road and me, too."

Lymph node mapping already helps treat other cancers, such as breast cancer. But cancers in organs that lie deep in the abdomen, such as gynecological ones, haven't proved as amenable to the technique.

Doctors tried using a radioactive substance to find the nodes. That, however, required personnel and a Geiger counter, making it time-consuming and expensive. They also tested a blue dye that was difficult to see.

Then a University of North Carolina gynecologist tried a fluorescent dye used in colon cancer. Not only did the compound stay in the lymph nodes long enough for doctors to find it, it also glowed through tissue, which could aid doctors working on obese patients.

That physician, Dr. John Boggess, a professor of gynecologic oncology at the UNC School of Medicine, assigned one of his fellows to develop a protocol for treatment.

Now he's participating in a trial that his former fellow, Rossi, is leading to show that it works. Other trials are under way but nothing approaching the scale of Rossi's, he said.

If this works, the process could help improve diagnosis and treatment. In some instances, doctors know cancer comes back even though they did not detect it in the lymph nodes. It's possible this technique will help doctors find the earliest beginnings of cancer that have previously gone unnoticed.